Earth ripper employing repetitive explosions

ABSTRACT

A tractor-drawn earth ripper is disclosed as including a combustion apparatus mounted on the tractor for providing repetitive explosions to aid the ripper in earth fracturing. A discharge conduit is provided for conducting gas under pressure to the lower end of a ripper shank to provide such explosions about the ripper tooth, and apparatus is disclosed for mounting the lower end of the discharge conduit on the lower end of the ripper shank.

F'IPTEll United States Patent 1191 [11] 3,924,897 Colburn, Jr. et al. Dec. 9, 1975 [54] EARTH RIPPER EMPLOYING REPETITIVE 2,874,656 2/1959 Bennett 111/7 EXPLOSIONS 3,600,116 8/1971 Clark 37/18 x 3,619,917 11/1971 Fischer 299/37 X Inventors: John W. Colburn, Jr-; Charles 1). 3,713,496 1/1973 Codlin 299/13 x Wood, III; Ronald J. Mathis; Allan of San Antomo Primary Examiner-Frank L. Abbott [73] Assignee: Southwest Research Institute, San Assistant Examinerwilliam Pate, In

Antonio, Tex. Attorney, Agent, or Firm l-lubbard, Thurman, Turner 22 Filed: Dec. 21, 1973 & Tucker 21 A 1. N .1 427,039 1 pp [57 ABSTRACT [52] CL 299/36. 37/18. 37/DIG A tractor-drawn earth ripper is disclosed as including {11/6 1 a combustion apparatus mounted on the tractor for 51 1111.01. E216 47/00 Providing repetitive explosions to aid the ripper [58] Field of Search 37 36 earth fracturing. A discharge conduit is provided for 172/699. 51 11176 conducting gas under pressure to the lower end of a ripper shank to provide such explosions about the rip- [56] References Cited per tooth, and apparatus is disclosed for mounting the lower end of the discharge conduit on the lower end UNITED STATES PATENTS of the pp Shank. 2,598,121 /1952 Hannibal 172/699 X 2,619,054 1 1/1952 Bell 37/193 4 Claims, 7 Drawing Figures l O 2 I PAH as a 15 12 11 I6 Dec. 9, 1975 Sheet 1 of 2 3,924,897

US. Patent FIG. 2

U.S. Patent Dec. 9, 1975 Sheet 2 of2 3,924,897

EARTH RIPPER EMPLOYING REPETITIVE EXPLOSIONS This invention relates to earth rippers and in one of its aspects to a tractor-drawn earth ripper employing repetitive explosions to aid in earth fracture by the ripper.

U.S. Pat. No. 3,461,577 shows a method and apparatus for repetitively displacing material by exploding a hydrocarbon fuel in a closed combustion chamber and directing the high pressure exhaust gas against the material to fragment and displace the material. The combustion chamber is provided with carburetion means for charging a fuel mixture under pressure into the combustion chamber. Combustion is initiated in the mixture by a suitable ignitor such as a spark or glow plug. An exhaust valve is provided for sealing the corn bustion chamber until a predetermined pressure is reached in the chamber subsequent to combustion. Thereafter, the exhaust valve opens so that the high pressure and temperature gases and combustion products are rapidly released and directed to fragment the soil.

In addition to the use of the combustion gases for fragmenting and dislodging soil and rock, other applications of this general type of device are also found in the prior art. For example, U.S. Pat. No. 3,572,273, shows the use of the repetitive combustion principle applied to the breaking and melting of ice. This principle may also be applied in conjunction with propulsion devices and for the production of seismic shock waves.

In U.S. Pat. No. 3,713,496, a tractor-drawn earth ripper is illustrated in which a combustion chamber and ignition source is provided in the ripper shank so that expanding gas may be discharged on either side of the ripper tooth to aid in earth fracture. However, while such apparatus may be effective in aiding inearth fracture, it requires substantial modification of the ripper shank which may structurally weaken the shank. Also, the apparatus of that patent includes a spark plug mounted in the lower end of the shank where it can be easily damaged by flying rock, exposed to moisture, and easily caked with dirt. Also, while the volume of explosive gases required for earth fracturing can be less than that required for use with the apparatus of U.S. Pat. Nos. 3,461,577, and 3,572,273, the provision of a combustion chamber in the ripper shank in U.S. Pat. No. 3,713,496 imposes too much of a limitation on the combustion volume, particularly if the structural integrity of the shank is to be maintained.

In co-pending patent application Ser. No. 365,629, entitled Sleeve Valve, filed may 31, 1973, an exhaust valve is disclosed which can be efficiently and rapidly operated to release pressure for use in repetitive explosion devices of the type described in U.S. Pat. Nos. 3,461,577 and 3,572,273. The valve comprises a generally cylindrical valve body having one or more ports in it, and a cylindrical valve sleeve reciprocable along the interior surface of the valve body and seats on a bottom cover plate defining an annular chamber with the seat. The valve sleeve is responsive to combustion in the valve body to open up exhaust ports and release high pressure combustion gases from an outlet in the body.

In order to overcome the shortcomings of the ripper plow of U.S. Pat. No. 3,713,496, the present invention provides a combustion apparatus for providing repetitive explosions, such as provided by the above referred to patent application Ser. No. 365,629, which may be mounted on a ripper plow to aid in earth fracture without requiring modification of the ripper and the ripper shank. This is accomplished by the present invention by mounting the combustion apparatus on a tractor having a ripper plow, and conducting exhaust gas from the combustion apparatus by a suitable conduit to the lower end of the ripper shank. The lower end of the ripper shank and the ripper tooth may be mounted on the conduit at its lower end so that exhaust gases from the combustiom apparatus are discharged about the ripper tooth and into fractures in the earth. It is preferred that the discharge opening of the discharge conduit be located substantially behind the tip of the ripper tooth so that loose soil or debris is substantially blocked from entering the discharge opening by the tooth itself, but that the discharge of gas be directed toward and near to the tooth. Also, it is preferred that the discharge conduit not extend below the ripper tooth so that during normal usage only the latter is in contact with intact rock until fracture occurs. In this manner, the ripper tooth serves as a wedge to open up the strata layers of rock to accept the gas discharge from the combustion apparatus. Also, with this arrangement, the ripper tooth can be easily made removable for replacement due to wear.

Thus, while apparatus in U.S. Pat. No. 3,461,577 relies on displacement of material by fuel-air explosions, the present invention provides for the fracturing of material without substantial displacement and can be used to fracture very hard materials, such as hard soil, rock, and frozen soil, either above or below water level. Displacement of the fractured material of this type is not desired because of the hazard of flying fragments and due to the difficulty in collecting dispersed fragments for transport and eventual removal to some other location. To prevent displacement, the tooth and discharge conduit immersed in the broken material are preferably narrow in width so that the broken material is little disturbed by the forward movement of the tooth. Further, the narrowness of the tooth and the conduit reduce the drawbar force needed to pull these components through the broken material.

By the use of the present invention, earth fracture is caused by a combination of two means. First, the drawbar pull of the tractor is transmitted through the connections between the tractor and the ripper apparatus to the point of the tooth and from there to the unbroken material to be fractured. This force is concentrated at the point of the tooth and is sufficient to initiate cracks in very hard materials, but frequently is insufficient to cause widespread fracture to the extent that the tractor can progress forward. When this occurs, the combustion apparatus of this invention is fired, and high pressure gas is forced down the discharge conduit and exits at the gas outlet near the point of the tooth. This gas enters the fractures in the material caused by the force of the tooth point and by the previous explosion. The gas expands the fractured area and produces additional broken material. The volume of gas is controlled by the combustion chamber volume so that material displacement can be limited. In this manner, repetitive explosions can be used to produce continuous or nearly continuous forward movement of the tractor in material that would otherwise be too hard to fracture on a continuous and economical basis.

While the specific combustion apparatus illustrated herein is similar to that shown in patent application Ser. No. 365,629, with the combustion chamber volume maintained as small as practical, other forms of combustion apparatus may be used, such as the apparatus illustrated in the co-pendin g patent application entitled Combustion Apparatus for Generating Repetitive Explosions, filed concurrently with this application.

DESCRIPTION OF THE DRAWINGS In the drawings, wherein preferred embodiments of this invention are illustrated, and like reference numerals are used throughout to designate like parts:

FIG. 1 is a view in elevation of a tractor-drawn rock ripper utilizing the present invention;

FIG. 2 is a side view of the tractor of FIG. 1, including a sectional view of one form of a combustion apparatus that may be used with the present invention;

FIG. 3 illustrates the operation of the apparatus of FIG. 1 during ignition and prior to discharge of gas pressure from the combustion apparatus;

FIG. 4 is a view similar to FIG. 3 illustrating the operation of the apparatus of FIG. 1 during discharge of gas pressure from the combustion apparatus;

FIG. 5 is a perspective view illustrating a preferred form of a discharge conduit suitable for conducting the high presusre gas discharged from the combustion apparatus to the lower end of the ripper shank;

FIG. 6 is a side view of elevation illustrating connection of the discharge conduit of FIG. 5 to the ripper shank; and

FIG. 7 is an end view in elevation of the apparatus of FIG. 6.

Referring now to FIG. 1, a conventional tractor 10 is illustrated as including a rock ripper or ripper plow apparatus 11 mounted on the rear thereof by a parallelogram-type linkage generally represented by the nu meral 12, and including pairs of parallel arms 13 and 14. A conventional rock ripper or plow 15 including a shank 16, a tooth 16a on the lower end of shank 16, and mounting block 17 for the upper end of shank 16, is supported by linkage 12, and linkage 12 is adapted to move ripper 15 from the position shown in FIG. 2 wherein the shank 16 is above the earth, to a position shown in FIGS. 3 and 4 in which the shank penetrates the earth. Linkage 12 maintains a constant shank tip ground angle regardless of the depth of the shank in the earth. Suitable means such an an hydraulic cylinder 18 may be provided to operate the linkage 12 to move shank 16 between the respective positions described. As noted, the apparatus described in conventional and can take many different forms to provide a tractordrawn earth ripper plow for earth and rock fracture.

However, as noted, the present invention provides repetitive explosions and gas discharges for use in aiding ripper plow 15 in earth fracture. For this purpose, a combustion apparatus 20 is mounted on the rear of tractor 10 and on ripper apparatus 11 in any suitable manner. Although combustion apparatus 20 may be of any suitable construction for providing repetitive gas discharges for aiding ripper plow 15, it is illustrated in FIGS. 2 4 as an apparatus employing a sleeve-type exhaust valve such as shown in patent application Ser. No. 365,629, referred to previously. Combustion apparatus 20 includes an upper vessel 21 providing a pressure chamber 22 and an inlet 23 for conducting a combustible gas, for exmample, propane, from fuel source (not shown) into chamber 22. Combustion apparatus also includes a lower body portion 24, providing a combustion chamber 25, and vessel 21 is mounted on lower body portion 24 so that chamber 25 is in fluid commutil nication with chamber 22. Body portion 24, which in cludes a discharge outlet 27 for the discharge of gas pressure out of chamber 25, is mounted on top of a cover plate 26. A precombustion chamber 28 is formed by a small housing 29 mounted externally of body portion 24 and fluid communication is provided between chamber 28 and chamber 25 by a conduit 36 connected therebetween. Ignition means such as spark plugs 31 are mounted in housing 29 to ignite gas in chamber 28 and thus gas in chamber 25. Spark plugs 31 are connected to a source of electrical current (now shown) for firing.

Bottom cover plate 26 provides a valve seat and a reciprocal sleeve valve 33 is mounted in a lower portion of body portion 24 for reciprocal movement be tween the position in which it seats on seat 32 and closes outlet 27, such as shown in FIGS. 2 and 3, to a position such as shown in FIG. 4 wherein sleeve valve 33 is open to permit discharge of gas under pressure from chamber 25 to outlet 27. The details of the con struction and operation of combustion apparatus 2f) are illustrated and described in the .previously referred to patent application and reference is made to that an plication for further description. However, in operation of the sleeve valve 33 during charging of chambers 22, 25 and 28 of an air-gas mixture to be ignited, outlet 27 is closed, and following ignition of gas in chambers and 25, raising the gas pressure substantially, valve member 33 is caused to open in response to the increased pressure to permit the discharge of gas under pressure through outlet 27.

While the ignition means may be mounted. in vessel 21 to provide for ignition, and chamber 23 dispensed with, because of the relatively smaller volume of chamber 28, more responsive ignition is realized by use of the smaller precombustion chamber 28. Also, to reduce the available combustion volume, a blind flange (not shown) with a suitable fuel inlet can be mounted on the top of body portion 24 in place of housing 21.. After combustion, the pressure in chamber 25 may be six to eight times the charging pressure.

An important feature of the present invention is that repetitive discharges of the gas under pressure from outlet 27 are conducted to the lower end of shank 16 and particularly about tooth 16a located on the lower end of shank 16. For this purpose, a discharge conduit 40 is mounted on apparatus 11 with its upper end 4Ila connected into outlet 27, and its lower end 4th; con nected to the lower portion of shank 16 adjacent to 16a. Conduit 40 is open at its lower end 4% and as shown in FIG. 2, it is preferred that this end extend towards tooth 16a and terminate behind tooth 16a so that gas is discharged towards the tooth from conduit 40.

Thus, by the provision of conduit 40 conducting discharge gas from combustion apparatus 20 to and about the tooth 16a, the gas discharge may be used to aid in earth fracturing as illustrated in FIGS. 3 and 4. in FIG. 3, the position of ripper 15 in the earth is illustrated prior to and during ignition and FIG. 4 illustrates the effect of the high pressure gas discharged from conduit 40 on the ripping operation of ripper 15. As shown in FIG. 3, prior to this discharge, fractures 50 may be present in the earth due to the loads placed on the earth by the tip of tooth 16a. Then, during ripping, when the forward progress of the ripper 15 becomes difficult, combustion apparatus 20 can be fired to provide discharge of gas into fractures 50 and about tooth 16a to aid in dislodging earth and rockadjacent tooth 16a, and in forming additional fractures 50 as shown in FIG. 4. Tractor can then be moved forward pulling ripper in the loose earth until itagain meets substantial obstruction. In themeantime, valve 33 'will have closed again upon release of pressure in chamber 25 so that the cycle of operation of combustion apparatus can be repeated. Thus, as needed, apparatus 20 can be repetitively fired to cause additional fracturing during movement of ripper 15. During actual use the timer interval between firing may be in the order of 3 4 seconds with the apparatus shown.

FIGS. 5 7 illustrate a preferred form of a conduit 40 and a preferred manner in which conduit 40 is mounted on shank 16 and tooth 16a. As illustrated, conduit 40, which may be a six inch diameter pipe, includes an end member 41 at its lower end 40b welded to the end of the pipe forming conduit 40, and extending therefrom. As shown in FIG. 5, an elongated slot 42 is provided in end member 41 and slot 42 is located on the top surface of member 41 and open towards the direction of travel of ripper 15. End 40b, of conduit 40 is curved as illustrated to generally follow the contour of shank 16, and member 41 includes an open end 43 which also faces toward the direction of travel of ripper 15. As illustrated in FIG. 6, shank 16 and tooth 16a are mounted in slot 42 and secured by welding along the edges of the slot, so that tooth 16a projects from end member 41 in the direction of movement of ripper 15, and downwardly beyond open end 43. This relationship is shown by the clearances 44 and 45 shown in FIG. 6. Thus, by this arrangement the gas discharge from open end 43 is directed towards tooth 16a and into the fractures in the earth adjacent tooth 16a. Also, during travel of ripper 15, and during the resulting explosions, rock and debris are substantially prevented by the presence of tooth 16a from plugging up opening 43. Since the gas discharge is directed towards tooth 16a, and the area to be fractured, this arrangement results in a relatively small amount of rock throw and good fracturing during operation. Also, by the modification illustrated to ripper 15, the resulting cut produced by the shank is maintained reasonably close to that produced by a standard ripper.

A further feature of the present design of shank 16 and conduit 40 is that the whole assembly can be kept relatively narrow to maximize its rock penetration capability as the ripper is drawn through the earth.

Thus, the present invention provides a rock ripper system which requires no substantial modification of the ripper shank or the ripper tooth, and which can be readily adapted to conventional rock rippers. The apparatus provided is relatively simple to operate, foolproof and inexpensive, and provides very little interference to the normal operation of the conventional rock ripper on which it is mounted. By use of the present invention, the capabilities of the conventional rock ripper can be practically extended to include what may have otherwise been unrippable rock.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An earth ripper for penetrating and fracturing earth, comprising, in combination:

a ripper shank adapted to be mounted on a tractor and including a ripper tooth mounted on the lower end thereof;

a combustion apparatus having a gas inlet, an ignition source, and a high pressure gas outlet, and adapted to be mounted on said tractor for generating repetitive discharge of gas under pressure at said gas outlet; and

a discharge conduit connected between said outlet and the lower end of said shank for conducting gas under pressure to an area adjacent to and about said tooth, said discharge conduit including an end member for connection to said ripper shank, said end member including an elongated slot for receipt of the lower end of said shank, said tooth extending outwardly from and in front of said end member in the direction of movement of said shank through the earth; and a discharge opening shielded by said tooth to prevent clogging thereof during operation of said earth ripper and disposed relative to said tooth so that gas discharged therefrom is substantially directed towards said tooth.

2. In an earth ripper including a tractor, a ripper plow mounted on the rear of said tractor and including a shank and a tooth on the end of said shank adapted to penetrate the earth, and means for supporting said ripper plow on said tractor and adapted to move it from a position wherein the shank and tooth are above the earth to a position wherein the tooth penetrates the earth, the improvement comprising combustion apparatus having a gas inlet, an ignition source, and a high pressure gas outlet mounted on said tractor for generating repetitive discharges of gas under pressure at said gas outlet; and a discharge conduit connected between said outlet and the lower end of said shank for conducting gas under pressure to an area adjacent to and about said tooth, said discharge conduit including an end member for connection to said ripper shank, said end member including'an elongated slot for receipt of the lower end of said shank said tooth extending outwardly from and in front ofsaid end member in the direction of movement of said shank through the earth; and a discharge opening shielded by said tooth to prevent clogging thereof during operation of said earth ripper and disposed relative to said tooth so that gas discharged therefrom is substantially directed towards said tooth.

3. A method of fracturing earth comprising the steps of:

utilizing an earth ripper to initially cause earth fracture adjacent the ripper;

generating a discharge of gas under pressure and conducting said discharge externally of the earth ripper to the lower end thereof to cause additional earth fracturing, said gas being discharged from behind the earth ripper and past the ripper in the direction of movement of the ripper; and

repeating the above two steps to provide the required earth fragmentation.

4. An earth ripper for penetrating and fracturing earth, comprising, in combination:

tive discharge of gas under pressure at said gas outlet;

8 a discharge conduit connected between said outlet and the lower end of said shank and mounted externally of said shank for conducting gas under pressure to an area adjacent to and about said tooth, and means mounted on the lower end of said ripper tooth and the lower end of said discharge conduit for directing the gas discharged from said discharge conduit toward and about said tooth.

UNHEE STATES PATENT OFFICE CERHMAE 0 CORRECTION PATENT NO. 3,924,897

DATED 3 December 9, 1975 INVENTOR(S) J hn w. colburn,

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 2, insert -substantialafter "requiring".

Column 3, line 24, presusre" should be --pressure-.

Column 3, line 45, "an" should be --as.

Column 3, line 48, "in" should be is.

Column 3, line 64, exmample should be -example--.

Column 3, line 64, insert -a after "from".

Column 5, line 10, "timer" should be -time.

,fiigncd and gcalcd this eighth Day of mum [SEAL] Amst:

RUTH cram" C. MARSHALLDANN Arresting Offiw (ammim'oner 01' Patent: and Trademark: 

1. An earth ripper for penetrating and fracturing earth, comprising, in combination: a ripper shank adapted to be mounted on a tractor and including a ripper tooth mounted on the lower end thereof; a combustion apparatus having a gas inlet, an ignition source, and a high pressure gas outlet, and adapted to be mounted on said tractor for generating repetitive discharge of gas under pressure at said gas outlet; and a discharge conduit connected between said outlet and the lower end of said shank for conducting gas under pressure to an area adjacent to and about said tooth, said discharge conduit including an end member for connection to said ripper shank, said end member including an elongated slot for receipt of the lower end of said shank, said tooth extending outwardly from and in front of said end member in the direction of movement of said shank through the earth; and a discharge opening shielded by said tooth to prevent clogging thereof during operation of said earth ripper and disposed relative to said tooth so that gas discharged therefrom is substantially directed towards said tooth.
 2. In an earth ripper including a tractor, a ripper plow mounted on the rear of said tractor and including a shank and a tooth on the end of said shank adapted to penetrate the earth, and means for supporting said ripper plow on said tractor and adapted to move it from a position wherein the shank and tooth are above the earth to a position wherein the tooth penetrates the earth, the improvement comprising combustion apparatus having a gas inlet, an ignition source, and a high pressure gas outlet mounted on said tractor for generating repetitive discharges of gas under pressure at said gas outlet; and a discharge conduit connected between said outlet and the lower end of said shank for conducting gas under pressure to an area adjacent to and about said tooth, said discharge conduit including an end member for connection to said ripper shank, said end member including an elongated slot for receipt of the lower end of said shank, said tooth extending outwardly from and in front of said end member in the direction of movement of said shank through the earth; and a discharge opening shielded by said tooth to prevent clogging thereof during operation of said earth ripper and disposed relative to said tooth so that gas discharged therefrom is substantially directed towards said tooth.
 3. A method of fracturing earth comprising the steps of: utilizing an earth ripper to initially cause earth fracture adjacent the ripper; generating a discharge of gas under pressure and conducting said discharge externally of the earth ripper to the lower end thereof to cause additional earth fracturing, said gas being discharged from behind the earth ripper and past the ripper in the direction of movement of the ripper; and repeating the above two steps to provide the required earth fragmentation.
 4. An earth ripper for penetrating and fracturing earth, comprising, in combination: a ripper shank adapted to be mounted on a tractor and including a ripper tooth mounted on the lower end thereof; a combustion apparatus having a gas inlet, an ignition source, and a high pressure gas outlet, and adapted to be mounted on said tractor for generating repetitive discharge of gas under pressure at said gas outlet; a discharge conduit connected between said outlet and the lower end of said shank and mounted externally of said shank for conducting gas under pressure to an area adjacent to and about said tooth, and means mounted on the lower end of said ripper tooth and the lower end of said discharge conduit for directing the gas discharged from said discharge conduit toward and about said tooth. 